Dental casting ring



Al O. BROPHY.

DENTAL CASTING RING.

l APPLICATION FILED AUGS, T921. l y 1,429,322, Patl'ltedept. 19, 1922.

Patented Sept. 19, 1922.

narran stares .ALLEN O. BROPHY, 0F OAK PARK, ILLINOIS.

DENTAL cAsrIlvG RING.

Application filed August 8, 1921. Serial No.y 490,586.

To all whom t 'may concer/1t Be it known that I, ALLEN O. Bnorr-IY, a citizen of the United States, residing at Oak Park, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Dental Casting Rings, of which the following is a specification;

The present invention relates in its broad aspect to dental apparatus, and more particularly hasl to do with an improved flask or casting ring intended primarily for use by dentists in the formation of inlays, clasps, saddles, plates, and the like.

Heretofore it has been customary to employ in this type of work an imperforate annular band into which the investment com.- pound in a iiowing state is poured about the wax impression or pattern supported by a wire within the band at approximately the center ofthe same. The principal objection to the use of this type of flask arises from the fact that because of the imperforate nature of the investment holderv too long a period of time is required in which to dry, burn out and heat the investment compound sufficiently to 'permit the pouring, forcing or drawing thereinto of the gold or other substance employed; and the liability of superheating the investment compound through confining of heat within the imperforate walls of the flaskis a further objection. y

The main and primary object, therefore, of this invention resides in the provision of an improved casting ring which is yadapted to expedite materially the drying, burning out and heating of the investment compound contained therein, and to prevent superheating of the `same throughl coniining heat within the flask. Other objects of the invention will become apparent as the nat-ure of the device is more fully understood from the following description and accompanying set of drawings wherein is set forth what is at present considered to be a preferred embodiment, together with one modification, of the invention. These particular structural embodiments, however, are presented mainly for 'the purpose of eXemplifying the invention, and are not intended to restrict unnecessarily the spirit of the same or the scope of the claims.

In the drawings,

Fig. 1 is a side-elevation of the present casting ring; l

F ig. 2 is a vertical diametric section on the u b with the investment compound;

line 2 2 of Fig. l, showin@ the ring'filled plan view of the ring as shown ings, it will be observedthat the casting ringy of this invention,` which is designated generally by the numeral 10, consists of two component ring members 11 and 12 which are concentrically and telescopically arranged. The innerer investment-holding member 11 is characterized by askeleton structure, having perforations 13 of circular or rectangular form cut at regular intervals in its cylindrical wall. An outwardly eX- tending annular projection 14 is provided at the top of this member'll above the adjacent perforation's, and is knurled as at 15 on f its outerv periphery in order to presenta.

suitable finger engagingsurface. "The outer member 12vis formed as a plain cylindrical sleeve the inner 'diameter of which corresponds substantially to the outer diameter of the member' 11 below the projection 14. When assembled with the perforated, investment-holding member 11 the sleeve member 12 snugly encompasses the perforated portion 'of the former `whereby to close effectively the apertures 13, and extends vertically downward from vthe underside of the projection 14 to a point even with the bottom of'the member 11.,`

The castingl ring isusedinthe following manner. 'After the waX impression or other form of patterny has been yprepared in the customary' way the'casting ringis assembled by sliding the sleeve member 12 thereof axially onto the perforated portion of the inner member 11, thereby providing what is to all appearances a one-piece open ended imperforate ring. The impression or patternis now supported within the contour of the ring by a wire or other means and the investment compound y16 poured therearound until the ring is substantially lled, it being of course understood that during this pouring operation the ring is placed upon a flat slab or table or upon a convex plate in order to form a Crucible in the investment and support the sprue wire upon open bottom of the same is precluded. As soon as the compound 16 has hardened or set sufficiently the casting ring l0 may be lifted and the sleeve portion l2 thereof Withdrawn axially from the investment-holding portion ll, leaving the compound 16 in a skeleton retaining frame exposed on all sides to the air whereby to further harden and dry thoroughly in a relatively short period of time.

When the mould has become thoroughly dry and sufficiently burned out and heated the moulten material or other substance used may be poured, forced or drawn thereinto with or Without the reassembly of the sleeve member 12 with the investment holder.

lVhile the device of this invention has been described hereabove primarily as a casting ring adapted for use by dentists, it Will be appreciated that the ring may be advantageously employed in other and diversied forms of casting by jewelers, etc., and no restriction of the uses to Which the invention may be put is therefore contemplated by the specific description of the manner of use of the same hereabove set forth.

While the previously described and illustrated embodiment of the invention employs an imperforate sleeve member for closing the perforations in the investment-holding member, it Will be understood that any equivalent closure means-such, for instance, as longitudinally hinged or otherwise secured cooperating` semi-cylindrical sleeve members` may be used to contact With and encompass the inner skeleton member and still remain Within the contemplation of the invention.

I claim:

l. A casting flask comprising a perforated investment holder, and removable means for closing the perforations therein to prevent egress of material therethrough.

2. A casting iiask comprising a perforated investment holder, and a member removably associated with said holder for preventing egress of material through the perforations therein. i

3. A casting ask comprising investment holder having perforated Wall portions, and a member removably associated With said holder for contacting said Wall portions to close the perforations in the same.

4. A casting flask comprising a perforated investment holder which is open at both ends, and a member removably associated with said holder and substantially in contact therewith about the perforations for closing the said perforations in the same.

5. A casting flask comprising a perforated investment holder, and a sleeve removably associated with said holder in telescopic relation thereto for closing the perforations in the same to prevent egress of material therethrough.

6. A casting flask comprising a perforated investment holder, and a sleeve removably associated vvith said holder in telescopic relation thereto for closing the perforations in the same from the outer side thereof to prevent egress of material therethrough.

7. A casting flask comprising a perforated investment holder of cylindrical form which is open at both ends and provided adjacent its upper end with an annular finger-engaging projection, and a cylindrical sleeve removably associated With said holder in concentric and telescopic relation thereto for closing the perforations in the same from the outer side thereof whereby to prevent egress of material therethrough.

8. A casting flask comprising a perforated investment holder of cylindrical form Which is open at both ends and provided adjacent its upper end With an annular finger-engaging projection, and a cylindrical sleeve removably associated With said holder in concentric and telescopic relation thereto for closing the perforations in the same from the outer side thereof whereby to prevent egress of material therethrough, said sleeve being adapted to slide axially ofthe investment holder and having a height corresponding to that of the holder less the height of the projection on the same.

In testimony whereofy l have hereunto signed my name.

ALLEN O. BROPHY. 

